A method of manufacturing a coated polymer substrate having low emissivity

Abstract

The invention relates to a method of manufacturing a coated polymer substrate having low emissivity properties and a high hardness. The method comprises the steps of providing a polymer substrate; applying at least one adhesion promoting layer on one side of said polymer substrate; applying at least one silica or silica-based layer on said at least one adhesion promoting layer by a sol-gel process. The invention further relates to a coated polymer substrate having low emissivity properties, to a glass substrate provided with a coated polymer substrate and to the use of such a coated substrate as substrate having low emissivity properties.

1 .- 15 . (canceled) 
     
     
         16 . A method to manufacture a coated polymer substrate having an emissivity lower than 0.1 and a hardness of at least 2H pencil hardness, the method comprising:
 (a) providing a polymer substrate;   (b) applying at least one adhesion promoting layer on one side of the polymer substrate;   (c) applying at least one silica or silica-based layer on the at least one adhesion promoting layer by a sol-gel process, starting from a mixture comprising at least one partially condensed alkoxide precursor.   
     
     
         17 . The method according to  claim 16 , wherein the silica or silica-based layer is obtained starting from a mixture comprising at least one partially condensed alkoxide precursor, a solvent and a catalyst. 
     
     
         18 . The method according to  claim 17 , wherein the catalyst comprises at least one base or at least one acid. 
     
     
         19 . The method according to  claim 16 , wherein the at least one partially condensed alkoxide precursor has a condensation degree of at least 60%. 
     
     
         20 . The method according to  claim 19 , wherein the alkoxide precursor is fully condensed in the sol. 
     
     
         21 . The method according to  claim 16 , wherein the alkoxide precursor is an alkoxy silane. 
     
     
         22 . The method according to  claim 21 , wherein the silane is selected from the group consisting of tetraethoxysilane (TEOS), tetramethoxysilane (TMOS), methyltriethoxysilane (MTES), vinyltrimethoxysilane (VTMS), 3-aminopropyltrimethoxysilane (APS), methacryloxypropyltrimethoxysilane (MAPTS), bis (triethoxysilyl)hexane, 1,6 bis (trimethoxysilyl) hexane or a combination thereof. 
     
     
         23 . The method according to  claim 16 , wherein the silica or silica-based layer is deposited by roll coating. 
     
     
         24 . The method according to  claim 16 , wherein the at least one adhesion promoting layer comprises a metal oxide selected from the group consisting of titanium oxide, indium oxide, tin oxide, zinc oxide, indium tin oxide, niobium oxide, zirconium oxide, either doped or non-doped and a mixture thereof. 
     
     
         25 . The method according to  claim 16 , wherein the at least one adhesion promoting layer is deposited by sputter deposition. 
     
     
         26 . A coated polymer substrate having low emissivity properties, the coated polymer substrate comprising:
 (a) a polymer substrate;   (b) at least one adhesion promoting layer deposited on one side of the polymer substrate;   (c) at least one silica or silica-based layer deposited on the adhesion promoting layer by a sol-gel process, starting from a mixture comprising at least one partially condensed alkoxide precursor, the coated polymer substrate having an emissivity lower than 0.1 and the at least one silica or silica-based layer having a hardness of at least 2H pencil hardness.   
     
     
         27 . The coated polymer substrate according to  claim 26 , wherein the silica or silica-based layer has a thickness ranging between 0.1 μm and 1 μm. 
     
     
         28 . The coated polymer substrate according to  claim 26 , wherein the adhesion promoting layer comprises a metal oxide, the metal oxide selected from the group consisting of titanium oxide, indium oxide, tin oxide, zinc oxide, indium tin oxide, niobium oxide, zirconium oxide, either doped or non-doped and a mixture thereof. 
     
     
         29 . The coated polymer substrate according to  claim 26 , wherein the adhesion promoting layer has a thickness ranging between 0.01 μm and 0.1 μm. 
     
     
         30 . A glass substrate with a coated polymer substrate according to  claim 26 .